feat(api): support prefixed IDs in routes and add unified mappers scaffolding

- Handlers parse IDs like kp_123 / tmdb_456 and set id_type accordingly
- Add KP->Unified and TMDB->Unified movie mappers (basic fields)
- Keep backward compatibility for numeric IDs

pkg/services/kp_mapper.go

@@ -167,6 +167,89 @@ func MapKPFilmToTVShow(kpFilm *KPFilm) *models.TVShow {
 	}
 }
 
+// Unified mappers with prefixed IDs
+func MapKPToUnified(kpFilm *KPFilm) *models.UnifiedContent {
+    if kpFilm == nil {
+        return nil
+    }
+
+    releaseDate := FormatKPDate(kpFilm.Year)
+    endDate := (*string)(nil)
+    if kpFilm.EndYear > 0 {
+        v := FormatKPDate(kpFilm.EndYear)
+        endDate = &v
+    }
+
+    genres := make([]models.UnifiedGenre, 0)
+    for _, g := range kpFilm.Genres {
+        genres = append(genres, models.UnifiedGenre{ID: strings.ToLower(g.Genre), Name: g.Genre})
+    }
+
+    poster := kpFilm.PosterUrlPreview
+    if poster == "" {
+        poster = kpFilm.PosterUrl
+    }
+
+    country := ""
+    if len(kpFilm.Countries) > 0 {
+        country = kpFilm.Countries[0].Country
+    }
+
+    title := kpFilm.NameRu
+    if title == "" {
+        title = kpFilm.NameEn
+    }
+    originalTitle := kpFilm.NameOriginal
+    if originalTitle == "" {
+        originalTitle = kpFilm.NameEn
+    }
+
+    var budgetPtr *int64
+    var revenuePtr *int64
+
+    external := models.UnifiedExternalIDs{KP: &kpFilm.KinopoiskId, TMDB: nil, IMDb: kpFilm.ImdbId}
+
+    return &models.UnifiedContent{
+        ID:            strconv.Itoa(kpFilm.KinopoiskId),
+        SourceID:      "kp_" + strconv.Itoa(kpFilm.KinopoiskId),
+        Title:         title,
+        OriginalTitle: originalTitle,
+        Description:   firstNonEmpty(kpFilm.Description, kpFilm.ShortDescription),
+        ReleaseDate:   releaseDate,
+        EndDate:       endDate,
+        Type:          mapKPTypeToUnified(kpFilm),
+        Genres:        genres,
+        Rating:        kpFilm.RatingKinopoisk,
+        PosterURL:     poster,
+        BackdropURL:   kpFilm.CoverUrl,
+        Director:      "",
+        Cast:          []models.UnifiedCastMember{},
+        Duration:      kpFilm.FilmLength,
+        Country:       country,
+        Language:      detectLanguage(kpFilm),
+        Budget:        budgetPtr,
+        Revenue:       revenuePtr,
+        IMDbID:        kpFilm.ImdbId,
+        ExternalIDs:   external,
+    }
+}
+
+func mapKPTypeToUnified(kp *KPFilm) string {
+    if kp.Serial || kp.Type == "TV_SERIES" || kp.Type == "MINI_SERIES" {
+        return "tv"
+    }
+    return "movie"
+}
+
+func firstNonEmpty(values ...string) string {
+    for _, v := range values {
+        if strings.TrimSpace(v) != "" {
+            return v
+        }
+    }
+    return ""
+}
+
 func MapKPSearchToTMDBResponse(kpSearch *KPSearchResponse) *models.TMDBResponse {
 	if kpSearch == nil {
 		return &models.TMDBResponse{

pkg/services/tmdb.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"net/url"
 	"strconv"
+	"strings"
 
 	"neomovies-api/pkg/models"
 )
@@ -179,6 +180,80 @@ func (s *TMDBService) GetTVShow(id int, language string) (*models.TVShow, error)
 	return &tvShow, err
 }
 
+// Map TMDB movie to unified content with prefixed IDs. Requires optional external IDs for imdbId.
+func MapTMDBToUnifiedMovie(movie *models.Movie, external *models.ExternalIDs) *models.UnifiedContent {
+    if movie == nil {
+        return nil
+    }
+
+    genres := make([]models.UnifiedGenre, 0, len(movie.Genres))
+    for _, g := range movie.Genres {
+        name := strings.TrimSpace(g.Name)
+        id := strings.ToLower(strings.ReplaceAll(name, " ", "-"))
+        if id == "" {
+            id = strconv.Itoa(g.ID)
+        }
+        genres = append(genres, models.UnifiedGenre{ID: id, Name: name})
+    }
+
+    var imdb string
+    if external != nil {
+        imdb = external.IMDbID
+    }
+
+    var budgetPtr *int64
+    if movie.Budget > 0 {
+        v := movie.Budget
+        budgetPtr = &v
+    }
+
+    var revenuePtr *int64
+    if movie.Revenue > 0 {
+        v := movie.Revenue
+        revenuePtr = &v
+    }
+
+    ext := models.UnifiedExternalIDs{
+        KP:   nil,
+        TMDB: &movie.ID,
+        IMDb: imdb,
+    }
+
+    return &models.UnifiedContent{
+        ID:            strconv.Itoa(movie.ID),
+        SourceID:      "tmdb_" + strconv.Itoa(movie.ID),
+        Title:         movie.Title,
+        OriginalTitle: movie.OriginalTitle,
+        Description:   movie.Overview,
+        ReleaseDate:   movie.ReleaseDate,
+        EndDate:       nil,
+        Type:          "movie",
+        Genres:        genres,
+        Rating:        movie.VoteAverage,
+        PosterURL:     movie.PosterPath,
+        BackdropURL:   movie.BackdropPath,
+        Director:      "",
+        Cast:          []models.UnifiedCastMember{},
+        Duration:      movie.Runtime,
+        Country:       firstCountry(movie.ProductionCountries),
+        Language:      movie.OriginalLanguage,
+        Budget:        budgetPtr,
+        Revenue:       revenuePtr,
+        IMDbID:        imdb,
+        ExternalIDs:   ext,
+    }
+}
+
+func firstCountry(countries []models.ProductionCountry) string {
+    if len(countries) == 0 {
+        return ""
+    }
+    if strings.TrimSpace(countries[0].Name) != "" {
+        return countries[0].Name
+    }
+    return countries[0].ISO31661
+}
+
 func (s *TMDBService) GetGenres(mediaType string, language string) (*models.GenresResponse, error) {
 	params := url.Values{}